1. Technical Field
The present invention relates to a loudspeaker which enables to faithfully reproduce original sound from media resource.
2. Background Art
In conventional enclosure-type or cabinet-type loudspeakers, a problem of back pressure of a driver is difficult to avoid. Only one solution to avoid it is to use a flat baffle plate. But an enormous flat baffle plate is required to configure a perfect loudspeaker by using a flat baffle plate. So, it has a fault in practical use.
A loudspeaker 10 illustrated in FIG. 2 employs a tandem drive system. The loudspeaker 10 is double enclosure type, having one enclosure 11a and a driver 12a, and another enclosure 11b and a driver 12b behind them. This is put into practical use by EgglestonWorks. In this, a diaphragm 13b of the rear driver 12b moves simultaneously in the same phase as a diaphragm 13a of the front driver 12a moves forward. It is said that this makes pressure in the front loudspeaker box always same as an outside pressure, and thereby the problem of back pressure of the diaphragm is resolved.
However, this system does not produce desired effect. The reason is that air moves slowly, air compresses and expands easily, and thereby the front diaphragm 13a begins to move before air delivered by the driver 12b arrives behind the front driver 12a. Therefore, a fundamental solution of the problem of back pressure is not achieved. This results that part of electric energy is not converted to vibrational energy of air, and becomes energy moving the driver and therefore the entire loudspeaker. Thus, a problem remains in accuracy of reproduced sound.